Research in Vestibular Science

Treatment of Migrainous Vertigo: Dong Uk Kim; Res Vestib Sci. 2012;11(Suppl 1):3-3.

1,738 View
24 Download

Abstract: Migraine is a common clinical syndrome characterized by episodic headache and associated with numerous other neurologic symptoms, including dizziness and vertigo. Migraine may be an important and under-diagnosed cause of various forms of episodic vertigo and there are many studies demonstrating a relationship between migraine disorders and dizziness. However the International Headache Society classification of migraine refers to vertigo as a migrainous symptom only in case of basilar migraine, an infrequent type of migraine that may include vertigo as an aura symptom. The concept of migrainous vertigo (MV) emerged from studies, with various definitions, in which an array of vestibular symptoms were described (i.e., true vertigo attacks, chronic dizziness, positional vertigo, motion-induced dizziness and motion sensitivity). MV patients may have symptoms that overlap with other clinical diagnoses such as Meniere’s disease or benign paroxysmal positioning vertigo, or anxiety associated dizziness adding to diagnostic confusion. It was frequently not possible to make a diagnosis of migraine on the basis of International Headache Society criteria; however the dramatic beneficial response to anti-migraine therapy supported the hypothesis that the vertigo was migrainous in nature. The poor understanding of the underlying pathophysiology of MV and the lack of a biologic marker in most cases compounds the challenge. No universally accepted diagnostic criteria exist for MV, complicating descriptive studies or prospective treatment trials. At present, it is generally accepted that the treatment of MV currently parallels to that of migrainous headache.

Art of History Taking in Dizzy Patients: Jae Ho Ban, Min Beom Kim; Res Vestib Sci. 2012;11(Suppl 1):3-5.

2,422 View
80 Download

Abstract PDF: Vertigo can be defined as an illusion or hallucination of movement. Vertigo can be caused by many different pathologies, some of which are potentially life threatening. The differential diagnosis of vertigo includes peripheral vestibular causes (i.e., those originating in the peripheral nervous system), central vestibular causes (i.e., those originating in the central nervous system), and other conditions. Benign paroxysmal positional vertigo, acute vestibular neuritis, and Ménière’s disease cause most cases of vertigo; however, the physicians who see the vertigo patients must consider other various causes including cerebrovascular disease, migraine, psychological disease, perilymphatic fistulas, multiple sclerosis, and intracranial neoplasms. History is the most important part of the assessment. Key questions should be asked and it is vital to establish if the patient is suffering from vertigo or some other complaint such as anxiety or syncope. History alone reveals the diagnosis in roughly three out of four patients complaining of dizziness, although the proportion in patients specifically complaining of vertigo is unknown. When collecting a patient’s history, the physician first must determine whether the patient truly has vertigo versus another type of dizziness. Once it is determined that a patient has vertigo, the next task is to determine whether the patient has a peripheral or central cause of vertigo. Key information from the history includes the timing and duration of the vertigo, what provokes or aggravates it, and whether any associated symptoms exist, especially neurologic symptoms and hearing loss. Other important clues to the diagnosis of vertigo may come from the patient’s medical history, including medications, trauma, or exposure to toxins. A neurological and otological examination should be performed, appropriate to the history. Associated neurologic signs and symptoms, such as nystagmus that does not lessen when the patient focuses, point to central (and often more serious) causes of vertigo, which require further work-up with selected laboratory and radiologic studies such as magnetic resonance imaging. Because patients with dizziness often have difficulty describing their symptoms, determining the cause can be challenging. An evidence-based approach using knowledge of key historic, physical examination, and radiologic findings for the causes of vertigo can help physicians establish a diagnosis and consider appropriate treatments in vertigo patients.

Evaluation and Treatment of Meniere’s Disease: Sae Young Kwon, Sung Kwang Hong; Res Vestib Sci. 2012;11(Suppl 1):4-8.

1,857 View
50 Download

Abstract: Meniere disease (MD) is an inner ear disorder characterized by episodic vertigo, fluctuating hearing loss, tinnitus and aural-fullness. Even though the pathologic process is not clearly understood, it well correlated with distortion of the membranous labyrinth by endolymphatic hydrops. The clinical presentation is the most important for diagnosing MD and its treatment option range from lifestyle modification or from medical therapy to ablation surgery according to the characteristics of patients with MD. This review describes the pathophyology of MD, and its evaluation and treatment.

Physical Examination of Dizzy Patients: Ji Soo Kim; Res Vestib Sci. 2012;11(Suppl 1):6-9.

1,882 View
55 Download

Abstract PDF: The bedside examination of dizzy patients should include a systematic evaluation of spontaneous and triggered nystagmus, and evaluation of the ocular motilities including saccades, smooth pursuit, optokinetic nystagmus, and the vestibulo-ocular reflex (VOR). Bedside evaluation of the VOR function includes head impulse test, visual enhancement of the VOR, and visual cancellation of the VOR. Examination of the balance and coordination function may disclose dysfunction of the cerebellar system. In contrast to the nystagmus of peripheral origin, the central nystagmus may show various patterns. Usually pure vertical and torsional nystagmus, direction-changing nystagmus, and nystagmus not suppressed by fixation indicates a central pathology. In case of positioning/positional nystagmus which does not follow the characteristic patterns of benign paroxysmal positional vertigo and does not respond to repeated canalith repositioning maneuvers, a possibility of central positional vertigo should be considered. Head impulse test is mostly negative in the central vestibulopathies, even in the presence of vertigo and spontaneous nystagmus. Disorders of ocular motility and coordination, and severe imbalance also suggest central lesions. Careful bedside evaluation provides valuable information on the underlying pathology of dizziness.

Interpretation of Basic Laboratory Tests in Dizzy Patients: Woo Sung Na, Jae Yun Jung, Myung-Whan Suh; Res Vestib Sci. 2012;11(Suppl 1):10-18.

1,676 View
47 Download

Abstract PDF: Dizziness is one of the most common complaint leading patients to visit their primary care physicians in older people. Despite its frequency, symptoms of dizziness can be difficult for the physician to categorize. Also many dizzy patients have hearing loss. The evaluation of patients with dizziness depends on not only the history of dizziness, physical findings but also basic laboratory tests such as audiometry, caloric test and ocular motor test. Based on these considerations, this article outlines the interpretation of basic laboratory tests which is fundamental in evaluating dizzy patients.

Introduction for Methodology of Basis Vestibular Research: Min Sun Kim¹, Ho Koo¹, Hak Seung Lee², Myoung Ae Choi¹, Nari Kim¹, Byung Rim Park¹; Res Vestib Sci. 2012;11(Suppl 1):11-11.

9,808 View
13 Download

Electrophysiologic Recording of Hair Cell: Gi Jung Im; Res Vestib Sci. 2012;11(Suppl 1):12-16.

19,926 View
12 Download

Abstract: Afferent cup-like terminal; calyx is innervated to type I hair cell, and efferent bouton is connected to calyx. Type II hair cell is directly connected to both afferent and efferent boutons. Vestibular hair cell can influence each other via complex connections of nervous system. Vesibular hair cells are also classified to three morphological classes of vestibular afferents: calyx, dimorphic, and bouton. Calyx type has large cuplike afferent terminals, dimorphic type has additional afferent connection with type II hair cells, and bouton type is a classic type II hair cell which both afferent and efferent terminals are contacted to base of cells. Calyx fibers of type I hair cells have highly irregular spontaneous discharges and the most phasic (adapting) response properties. Otherwise, neural discharge properties of type II hair cells are the most regular and least phasic (tonic). Vestibular system provides sensory information using a complex hair cell system, which has cell-specific ion channels.

Electrophysiology of Vestibular System: Eunjin Park¹, Kyu-Sung Kim², Jihoon Jo³; Res Vestib Sci. 2012;11(Suppl 1):17-20.

1,702 View
16 Download

Abstract: Electrophysiological study of the vestibular nerve cells how to fish, amphibians, reptiles, birds and mammals from a variety of research results. However, the small number of experimental animals used in this study toward higher organisms is inconvenient. Thus, in vitro or in vivo experiments using a mouse or a rat, electrophysiological studies in the vestibular organs of the study, a statistically significant level, many of the experimental results can be achieved. It is easier to prepare for dealing with experimental laboratory animals. Gene mouse mutants related to the genetic map of the mouse study, there has been significant progress, as well as vestibular and auditory development has become. In conclusion, applied or basic research associated with the vestibular nerve in rodents, such as rats and electrophysiological studies, considering the characteristics of the vestibular system, and how the mouse is a need for the development of an experimental model. In this paper, we briefly explained the common electrophysiological studies, experimental methods, and applied on the vestibular nerve afferent examples.

Interpretation of Nystagmus: Kyu-Hee Han, Ja-Won Koo; Res Vestib Sci. 2012;11(Suppl 1):19-24.

1,897 View
66 Download

Abstract PDF: Nystagmus is defined as spontaneous, involuntary, to-and-fro movement of eyes caused by retinal slip. Observation of nystagmus is the core examination in patients with vertigo or balance disorders. The interpretation of nystagmus requires familiarity with the types of nystagmus and differential diagnosis for common diseases and location of lesion. Here we review the features of nystagmus arising from different conditions and related disease.

Functional Mapping of the Central Vestibular System: Min Sun Kim¹, Ho Koo¹, Hak Seung Lee², Myoung Ae Choi¹, Nari Kim¹, Byung Rim Park¹; Res Vestib Sci. 2012;11(Suppl 1):21-21.

1,484 View
14 Download

3-Dimensional Vestibuloocular Reflex Recordings of C57BL/6 Mouse Using 385 nm Ultra-Violet Lighting: Mi Joo Kim¹, Gyu Cheol Han²; Res Vestib Sci. 2012;11(Suppl 1):22-28.

1,820 View
10 Download

Abstract: Background and Objectives: Non-primate Vertebrates are widely used to study vestibular system since their vestibular reflex is very similar to the one in humans. Recording vestibulo-ocular reflex (VOR) in laboratory animals such as mice is technically very sophisticated. Thus, three-dimensional (3D) recording method for VOR has been newly developed in which a 200 μm-sized marker is attached to the eyeball of a C57BL/6 mouse and a certain ultra-violet (UV) ray is illuminated to it.
Materials and Methods: A bolt for head fixation was permanently implanted on the skull under inhalation anesthesia. The range of given rotational stimulation was ±100°/sec with the frequency of 0.1 Hz and 0.2 Hz. The analysis was performed with the data gathered from at least three cycles, and the maximum slow-phase velocity of the eyeball was averaged from the data to calculate gain, phase and symmetry.
Results: In eyeball rotation data recorded with a video-nystagmus-recording machine with UV ray illumination, an error occurred by eyeball rotation were ignorable since its diameter was very small (error rate <1 pixel). Preoperatively undergiven. 0.1 Hz stimulation, average maximum slow-phase velocity was 14.95±4.80°/sec in the clockwise rotation and 14.94±4.01°/sec to the opposite.
Conclusion: The nystagmus was able to be quantified in C57BL/6 mice by using 3D recording method for VOR with 385 nm UV ray illumination.

Easy Approach to the Dizzy Patient: Imaging: Tae-Kyeong Lee; Res Vestib Sci. 2012;11(Suppl 1):25-28.

1,710 View
24 Download

Abstract PDF: Imaging of the audiovestibular system has become an important element for the approach to the dizzy patient. Among many imaging tools, magnetic resonance (MR) imaging has been considered to have a high sensitivity and specificity for diagnosis of lesions in the retrocochlear vestibular system as compared with computed tomography. In addition, considerable subsets of sinister central vestibular disorders with subtle clues can be identified by MR imaging. However, its high cost precludes its routine use for screening all patients with vestibular disorders. Therefore, MR imaging should be considered only to the patients with a risk of having retrocochlear lesions including vestibular schwannoma, cerebellopontine angle tumors, and demyelinating or vascular lesions in the posterior fossa. There have been efforts to identify the factors implying each of retrocochlear lesion, but no definite indication for imaging have suggested. The presenting pattern of dizziness, accompanying features, neurootological bed side and laboratory examination can provide useful information for recognizing factors suggesting retrocochlear lesions. The aim of this review was to discuss the indication for the neuro-otologic imaging in approaching to the dizzy patients.

Vestibular Afferent Responses to Infrared Photo-Stimulation of the Mammalian Labyrinth: Joong Ho Ahn¹, Peter Boutros, BS^1,2,3, David M Lasker, BS, MBA¹, Chenkai Dai¹, Gene Y Fridman¹, Charles C. Della Santina^1,2; Res Vestib Sci. 2012;11(Suppl 1):31-31.

2,881 View
0 Download

Abstract: Background and Objectives: Current multichannel vestibular prosthesis under development has problems to overcome, for example, electrical currents easily spread over the adjacent ampullae such as horizontal and superior canal ampullae and there is asymmetry between excitation and inhibition response due to the characteristics of vestibular nerve. Pulsed infrared radiation (IR) is known for more spatially selective stimulation of cranial nerve than electric current. We stimulated crista ampullaris of chinchilla with IR to collect various responding vestibular afferents from single unit recordings.
Materials and Methods: Adult female chinchillas (450-650 g) were used in this study. After exposure of superior vestibular nerve for single unit recording, we opened a hole at the lower part of superior semicircular canal (SCC) to introduce the optical fiber (400 μm in diameter) over the crista ampullaris. IR photo-stimulation was delivered using Capella pulsed infrared laser (Lockheed-Martin Aculight, Bothell, WA, USA) with optical fiber (400 μm in diameter).
Results: We’ve recorded total 49 units from SCC consisted of superior (n=19) and horizontal (n=30). Among them, there were three kinds of responses from regular afferents (excitation [n=17], inhibition [N=12], and mixed [N=6]) and two kinds of responses from irregular afferents (excitation [N=5] and inhibition [N=9]) in this study. Regular afferents showed pretty small time constants that were less than 1 sec and irregular afferents had abrupt rise (excitation) and shut-down (inhibition) responses. During recording phase-locking responses from excitatory irregular afferents, there were 2.1±3.5 msec between neuronal responses and laser pulses. Pulse width and pulse rate of IR modulated afferent responses according to the sum of energy, while the wavelength over 1,863-1,877 nm had little or no effect.
Conclusion: From these results, we showed that IR photo-stimulation could modulate various responses from stimulation of crista ampullaris of mammals, which consisted of 5 different responses from regular and irregular afferents including phase-locking responses.

Electrophysiological Approach on Vestibulocerebellar Research: Chang-Hee Kim; Res Vestib Sci. 2012;11(Suppl 1):32-35.

1,550 View
11 Download

Abstract: The vestibular nuclei have extensive afferent and efferent connections with posterior cerebellum which can be referred to as vestibulocerebellum. Some of vestibular primary afferents also project to the ipsilateral uvula-nodulus-flocculus as mossy fibers. The secondary vestibular fibers are distributed bilaterally. The Purkinje cells in the cerebellar cortex receive climbing fiber input which is originated from the contralateral inferior olive; the dorsomedial cell column and β-nucleus. Purkinje cells respond to vestibular stimulation with antiphasic modulation of climbing fiber responses and simple spikes. The vestibulocerebellum imposes a vestibular coordinate system on postural responses and permits adaptive guidance of movement.

Three-Dimensional Analysis of Eye Movement: Kyu-Sung Kim; Res Vestib Sci. 2012;11(Suppl 1):33-37.

1,672 View
23 Download

Abstract PDF: The accurate measurement of eye movements is important in the field of vestibular and oculomotor research. These requirement has led to the development of different approaches. The primary methods for three dimensional eye measurement are the scleral search coil and video-oculography. The authod review the basic mathematics for the representation of three-dimensional eye movements including rotation matrices and vectors and quaternions.

Previous issues